Hi Benjamin,
I’m not quite sure I understand your question, so you might have to help me here. You said “when a client books an event” which is not something our calendar plugin is designed to do. The plugin displays events on a calendar in several views, but it’s not a true booking solution.
Unless perhaps you were referring to our Community Events add-on which allows people to add events to your calendar? If that’s the case, you could block roles from accessing it, which could effectively limit it to members if your site is set up that way.
If by chance when you said “when a client books an event” you meant something more like purchased a ticket to an event, I don’t think that is something that could be limited to members only unless somehow the calendar itself was limited to members.
It is entirely possible that I’ve not answered your question. Please let me know what I’ve missed and if there’s anything else I can help you with.
— Julie